The influence of temperature on the internal resistance characteristics of lithium iron phosphate batteries

What effect does temperature have on the internal resistance characteristics of a dynamic lithium iron phosphate battery? The internal resistance of a lithium iron phosphate battery is an important parameter to measure the difficulty of conducting ions and electrons in the battery. It directly determines the power characteristics of the battery, so it is very important for electric vehicles. Power performance has an important impact. At the same time, the internal resistance also determines the heat generated by the battery. The actual working environment of electric vehicles has a wide temperature range, and the internal resistance of the battery varies with temperature and working conditions. Knowing the internal relationship between battery internal resistance and temperature, SOC and charge-discharge ratio can provide a better basis for the simulation of battery heat generation models and the design of thermal management systems. The temperature characteristics of lithium iron phosphate power lithium-ion battery, 10 o’clock 25 to 40 ℃ shows the ohmic resistance and polarization resistance of the battery during charging and discharging, as the temperature increases, decreases and the ohmic resistance changes at different temperatures. In polarization, the low-temperature change of ohmic resistivity is higher than the high-temperature lithium battery protection board principle: lithium battery needs to be protected due to its own characteristics. Since the lithium battery itself is made of materials that prevent it from charging and discharging, overcharging, short-circuiting, and charging and discharging at ultra-high temperatures, the lithium battery package is always accompanied by a delicate protection board and a current fuse. The protection function of the lithium battery pack is usually completed by the cooperation of the protection circuit board and the current devices such as PTC. The protection board is composed of electronic circuits, which can accurately monitor the voltage of the battery and the current of the charging and discharging circuit within the range of -40°C to +85°C, and control the on and off of the current circuit in time. PTC prevents serious damage to the battery at high temperatures. Ordinary lithium battery protection boards usually include control ICs, MOS switches, resistors, capacitors and auxiliary device fuses, PTC, NTC, ID, memory, etc. When everything is normal, the control IC controls the MOS switch so that the battery and external circuits can be turned on. When the battery voltage or circuit current exceeds the specified value, it immediately controls the MOS switch to protect the safety of the battery. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: New lithium battery technology can cut off the current by itself